To improve the versatility of their 6x6 fixed lens Rolleiflex, Franke & Heidecke introduced the Rolleikin and the Rolleinars.
The Rolleikin is a kit to convert the camera from 6x6 to 24x36 format using common 35mm film.
The Rolleinars 1, 2 and 3, are coupled auxiliary lenses (1 for the viewing and 1 for the taking lens of the camera) in three different magnifying degrees, useful for portraits, particulars and kinf of macro.
Here's what you could get!